One of the aspects of secure messaging protocols, including the S/MIME standard is the use of signed receipts. The receipt is generally bound to an S/MIME message through an associated digital signature. Accordingly, signed receipts only pertain to signed S/MIME messages. Returning a signed receipt to a sender of the message serves to provide proof of delivery of the message, and allows the sender to demonstrate to a third party that the recipient was able to verify the digital signature of the original message so as to authenticate the sender and/or authenticate data included in the message. This is particularly important in processes that are dependent on authentication and non-repudiation such as processes related to e-commerce or other communications or transactions where authentication or non-repudiation may be a factor.
In the drawings, preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended as a definition of the limits of the invention.